Marriage Penalty Relief Act of 2003

Marriage Penalty Relief Act of 2003 - Amends the Internal Revenue Code (IRC) to provide that the basic standard deduction on a joint return shall be equal to 200 percent of the dollar amount of an individual who is not married.Makes the maximum taxable income in the lowest joint bracket equal to double the maximum taxable income in the lowest single filer bracket.Increases the earned income credit phaseout amount on a joint return by $3,000.